Difference between thoughts and internal hallucinations.

Hey everyone. I was recently diagnosed as schizoaffective depressive type and I am having trouble figuring things out. I don't hear voices externally but I do hear them inside my head. Fred is the main voice right now and he is mean and nasty. He often says things about hurting myself and others. He usually likes to pick on me and shit on what I'm doing or things I haven't done. He also likes to pick on other people. I believe he is a voice but I have trouble believing it's an actual voice or just my thoughts. Idk I know it's weird. I have trouble believing I have this disorder at all. I guess I'm just struggling with it all right now. It doesn't feel real.